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Chapter 6: The Electromagnetic Process

Considered from the viewpoint of basic military objectives, the single most important problem of the Manhattan Project was how to produce fissionable materials in the quantity and of the quality required to make an atomic bomb. By the end of 1942, because project leaders were reasonably certain that a considerably greater amount of fissionable materials than had been previously estimated would be needed, the Military Policy Committee decided to proceed with full-scale development of three production methods: for plutonium, the pile process; for U-235, the gaseous diffusion and electromagnetic processes. Of the three, project leaders agreed that the electromagnetic method most likely would be the first to produce an appreciable quantity of fissionable material, although not nearly enough for an atomic weapon.

There remained, however, some major reservations concerning the feasibility of the electromagnetic method as a large-scale production process. In its recommendation that the Army initiate construction of a 100-grams-per-day electromagnetic plant, the S-1 Executive Committee indicated that all contractual arrangements should be drawn up so that they could be readily canceled should “subsequent developments warrant ... a change of plans.”1 Similarly, following its fact-finding tour of the project’s research laboratories, the Lewis reviewing committee reported: “We do not see that the electromagnetic method presents a practical solution to the military problem at its present capacity. ...”2 An electromagnetic plant capable of producing 1 kilogram of fissionable material per day would require at least twenty-two thousand separation tanks, whereas the same output could be achieved by a diffusion plant of only forty-six hundred stages or three 250,000-kilowatt plutonium piles. These figures implied that an electromagnetic plant would take longer to build, use up far more scarce materials and manpower, require more electrical power to operate, and cost a much greater sum than either a gaseous diffusion or plutonium plant with equivalent production capabilities.3

In spite of the drawbacks of the electromagnetic method as a large-scale industrial process,

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each of the three committees concluded that the method presented advantages which outweighed its obvious defects. Based on a proven laboratory tool, the mass spectrograph, the electromagnetic method was the most certain of the processes to produce at least some fissionable material, albeit not very efficiently. Also, a mass production level could be more rapidly attained because an electromagnetic plant could be built in relatively small, self-sufficient sections, each of which could begin producing material as soon as it was completed. Neither the gaseous diffusion nor pile methods had this advantage. Finally, too, General Groves and S-1 Chairman James B. Conant, as well as several of the other project leaders, perceived the leadership of Ernest Lawrence as giving a distinct advantage to the electromagnetic process. The University of California scientist repeatedly had demonstrated an ability to find quick, practical solutions to even the most difficult technical problems that had arisen in development of the process.4

Electromagnetic Research and the Army, 1942–1943

Only weeks after Colonel Marshall’s assignment as district engineer, the Army began to take over administration of engineering, construction, procurement, and related aspects of the electromagnetic program, leaving to the Office of Scientific Research and Development (OSRD) continued supervision of research and development activities and fiscal and budgetary matters. In August, Marshall opened the California Area Engineers Office at Berkeley and assigned Maj. Thomas T. Crenshaw as area engineer and Capt. Harold. A. Fidler as his assistant. Crenshaw soon established himself in the university’s Donner Laboratory, adjacent to Lawrence’s office.5

During the fall and winter of 1942–43, Major Crenshaw’s office became increasingly involved in procurement of materials and equipment for the research and development program and with providing liaison between the Berkeley program and other elements of the atomic project. In this period, an important phase of the staff’s liaison function was arranging visits to the Radiation Laboratory for the various individuals and groups involved in trying to decide what the role of the electromagnetic process should be.6

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These visitors came to learn firsthand more about Lawrence’s method and how it was progressing. After clearances by Crenshaw’s staff and the laboratory’s security officials, Lawrence and his technical staff showed them the impressive physical facilities and equipment. They toured the conventional laboratories on the university grounds and then the great domed cyclotron building with its adjacent shops and facilities located in the hilly area east of the main campus. There they observed the intensive investigations under way into the physics and chemistry of separating U-235 from ordinary uranium by the electromagnetic method. Lawrence had committed the largest part of his staff and resources to the physics or physical aspects of the separation process, centering this research in two buildings, one housing a 37-inch magnet and the other a 184-inch magnet. The availability of these cyclotron magnets, which were exceptional in size and strength, was the single most important factor in making possible research into the feasibility of the electromagnetic method as a production process. Research into the chemical aspects of the separation process under Lawrence’s direction was a much smaller program, with laboratory investigations in progress at both the Berkeley and Davis campuses of the University of California.7

Lawrence and his scientist colleagues repeatedly emphasized to visitors that their ultimate success or failure depended on development of the calutron – a name derived from the words California, university, and cyclotron. If they could redesign the calutron, a novel hybridization of two well-known laboratory tools – the mass spectrograph and the cyclotron magnet – so that it would operate not only intermittently, as in the laboratory, but also on an around-the-clock, day-after-day, month-after-month basis without breakdown, then they would have the means for producing a significant amount of enriched uranium for an atomic weapon.

Lawrence had made some design modifications in the first calutron, installed in the 37-inch magnet, following successful experiments in February 1942. He found, however, that he was unable to test the validity of these changes until he had access to a more powerful magnetic field. This became available in the spring with completion of the 184-inch magnet. The redesigned calutron became the prototype for the first production units at the Tennessee plant. Mounted on a metal door, this calutron could be taken out of its vacuum tank as a single unit, which greatly facilitated recovery of any of the valuable uranium feed material adhering to components and also expedited reloading and maintenance.

At the same time, Lawrence’s group had also developed the essential supporting components – magnet, vacuum pumps, cooling systems, and

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electrical power and control equipment. While these components were more conventional in design and function, they still had to be adapted to conform to the requirements of the electromagnetic process. The design engineers, for example, decided that the most efficient layout for the magnets and tanks was in an oval-shaped pattern, thus creating the racetrack configuration that characterized each major element of the production plant. A special system of pumps achieved and maintained the required vacuum equivalent of one one-hundred-millionth of normal atmospheric pressure in hundreds of calutron tanks.

Involving less space, fewer personnel, and mainly conventional procedures, the chemical aspects of the electromagnetic process must have appeared far less important; nevertheless, both the first and final stages of the process were essentially chemical operations and required new techniques and chemical substances about which relatively little was known. For the first stage the chemists had to develop a method of large-scale production of uranium tetrachloride, the most promising feed material for the calutrons. For the last stage they had to devise an efficient method to extract the enriched uranium produced by the calutrons and prepare it for use by the Los Alamos Laboratory scientists in developing an atomic bomb. By early 1943, the chemists had made substantial progress on both the feed material and extraction techniques.

Virtually all who visited the Radiation Laboratory at Berkeley came away impressed with the feasibility of the electromagnetic research program and with the eminently empirical approach of Lawrence and his staff. This approach, characterized by a frequently demonstrated talent for finding practical solutions to every problem, inspired project leaders with further confidence in Lawrence’s process as they prepared to transform the research data and devices into an industrial production plant at the Tennessee site.

Research and Development, 1943–1945: Radiation Laboratory

As the electromagnetic program shifted from basic research to the problems of designing, building, and operating a major production plant, the Army brought the project more directly under its administrative jurisdiction. Replacing OSRD contracts with War Department contracts was an important step in attaining this goal.

The University of California accepted a letter contract from the district engineer, effective 1 April 1943, pending the working out of details of a formal War Department contract. Then on the sixteenth, representatives of the Manhattan District, OSRD, and the university’s Board of Regents reached final agreement on terms of a new prime contract covering most aspects of the atomic research program in progress at the Radiation Laboratory. The new contract went into effect on 1 May, bringing to an end the OSRD’s formal connection with the California project. Henceforth, until the Army terminated control of the atomic energy program at the end of 1946, this new agreement,

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renewed annually, provided the contractual basis for continuing the research and development activities requisite to construction and operation of the electromagnetic plant in Tennessee. In recognition of the overriding requirements of security, the regents assented to leaving all details of managing the program as they related to the university to their secretary, Robert M. Underhill, and to Lawrence. Some subsequent modifications in the prime contract relating to health and chemistry activities did not result in major changes in the Radiation Laboratory program, nor in the Army’s relationship to it.8

In general, fiscal arrangements remained the same as they had been under the OSRD contract, with one significant exception. The War Department contract provided that an amount equal to 25 percent of the total funds allotted for salaries and wages could be used by the university to defray its overhead expenses in operating the Radiation Laboratory; the OSRD contract had provided 30 percent for this purpose. Partly in reaction to this reduction in overhead allotment, in November 1943 business representatives of the University of California, University of Chicago, and Columbia University requested the Manhattan District to include a provision in prime contracts guaranteeing the universities, in view of their nonprofit status, against a profit or loss in administering atomic research programs. Following several months of negotiation with the universities, the District agreed in May 1944 that the government would compensate them if their overhead costs should exceed their 25 percent allowance and, conversely, they would return to the government any surplus that might result from this allowance.

At the same time, the District added a provision in the prime contracts with California, Chicago, and Columbia for a so-called welfare fund. Thus, in the case of California, the government established a fund of $500,000, which was to continue in existence for a period of ten years after termination of its contract with the War Department. Any claims made by Radiation Laboratory employees or their relatives during that time because of death or disability resulting from a specified list of unusual hazards in atomic research activities – for example, radioactivity, high voltages, and movement of objects by magnetic forces – would be paid from this fund. The government provided the money for the fund and the university administered it with assistance of a private insurance company. The welfare fund took the place of the

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OSRD’s private indemnification insurance, which the District had continued only until such time as a government-financed system could be established.9

The Army’s first major administrative task after the formal contract became effective was to supervise preparation of the program’s fiscal year (FY) 1944 budget. As of mid-1943, cost of the program had reached about $500,000 a month, and was following an upward trend. District and university officials agreed upon a request for $7.5 million (an average of $625,000 per month) for FY 1944. By November, however, Regents Secretary Underhill was warning Captain Fidler, who had replaced Major Crenshaw as area engineer, that even this increased sum was not likely to be enough to meet mushrooming costs. Underhill estimated that the university would need an additional $1.5 to $2 million in the remaining months of FY 1944. Consequently, the District approved a supplementary appropriation, bringing total cost to $9.5 million.

The Army’s negotiations with the University of California for the FY 1944 budget set the pattern for subsequent years. Even after the electromagnetic production plant began operations in the spring of 1944, the electromagnetic research program continued to require a large staff to solve production problems and make improvements in plant operations. Thus, for the FY 1945 budget, the Army scheduled $8.5 million, although only $6.5 million was actually expended. By the time the war ended in August 1945, total outlay for the electromagnetic research program had reached about $20 million – some $3.7 million under OSRD contracts before 1 May 1943 and the remainder under the War Department contract.10

Increases in cost reflected the very rapid expansion of the Radiation Laboratory, both in terms of personnel and physical facilities. In May 1943, when the Army assumed full responsibility for the research program, the laboratory was occupying a number of buildings in two different locations on the Berkeley campus. Starting out modestly in 1941 in the prewar Radiation Laboratory building, atomic research activities gradually had spread into four adjacent structures, including the new Donner Laboratory, and, by mid-1942, to the new 184-inch cyclotron building in Berkeley Hills. Soon the circular-shaped cyclotron building, standing on the slope of a hill some 900 feet above the campus proper, was ringed with smaller additional structures housing a machine shop, chemistry laboratories, warehouses, and other facilities essential to operating and testing calutrons and other equipment prototypes designed for the production plant in

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Tennessee. Part of the chemistry program, too, had overflowed facilities on the Berkeley campus and been moved to the University of California’s School of Agriculture at Davis. For each new structure or renovation, Lawrence and his staff laid out preliminary plans and estimates, which went to the area engineer’s office for approval and checking. Detailed supervision of construction was left to Radiation Laboratory business manager Kenneth Priestly. To expedite the work and minimize security problems, Priestly let contracts to the local firms that the university had employed extensively in the past. For the same reasons, most contracts were of the fixed-fee or lump-sum type. By mid-1945, Priestly had allocated for various types of construction more than $300,000 from funds allotted under the University of California’s War Department contract.11

By far, the largest expenditures were for salaries and wages of the research staff and for the laboratory equipment and materials they needed. Annual payroll costs were running at a level of nearly $3 million in May 1943, when the Army assumed full control of the Manhattan Project, and had reached a high point of about $3.7 million a year later. Equipment and other expenses, although somewhat less than personnel, attained a maximum of nearly $300,000 a month in November 1943.12

Starting in 1941 with personnel of the University of California’s Radiation Laboratory, which Lawrence had been building up since the 1930s, the staff at Berkeley grew rapidly. By May 1943, as primary emphasis began to shift from basic research to engineering and developmental problems and training of operational personnel for the Tennessee plant, it numbered almost nine hundred scientists, technicians, engineers, mechanics, clerks, skilled workers, and others. By mid-1944, there were nearly twelve hundred on the Radiation Laboratory payroll, and total employment remained well above one thousand until the end of the war.13

The basic organization of the Radiation Laboratory had taken shape under Lawrence’s guidance in the years immediately preceding the outbreak of World War II and conformed, more or less, to the conventional pattern for peacetime academic research programs, with a major division into research and administrative staffs. While Lawrence, as director, theoretically exercised equal control over both divisions, he devoted his energies to the research staff, delegating to the OSRD and then the Army the administration of nonscientific activities. Major responsibilities for these activities devolved upon Captain Fidler, the area engineer. Fidler worked closely with Regents Secretary Underhill and also with Priestly who,

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as the laboratory’s business manager, supervised administration of finances and personnel.14

In providing personnel, security, and other administrative services for the research staff, the area engineer dealt with teams of scientists and technicians organized along functional lines under three broad areas of investigation. The physics division, by far the largest, worked on the experimental calutrons, vacuum problems, mechanical and electrical design, reassembly of equipment, and fundamental physical research. The chemistry division, much smaller, investigated problems of preparing feed material for the calutrons and recovery and purification of their output of U-235 and ordinary uranium. The biological group constituted a subsidiary element of the Manhattan District’s medical research program that had its headquarters at the Metallurgical Laboratory in Chicago. The area engineer provided its director with administrative support in coordinating the activities of his group with Lawrence’s program, based upon primary guidance from the Chicago medical scientists. The Army was helpful, too, in assisting the laboratory in recruitment and maintenance of a staff of several hundred technicians and skilled workmen, who supported the work of the scientists and engineers.

Adding to the complexity of administering the Radiation Laboratory were the periodic influxes of scientific, engineering, and other technical delegations not only from the major American contractors but also those from abroad. Such firms as the Stone and Webster Engineering Corporation, Westinghouse Electric and Manufacturing Company, and especially the Tennessee Eastman Corporation sent their personnel to Berkeley to assist in plant development, or for orientation and training in the electromagnetic process. And in November 1943, Australian physicist Marcus L. E. Oliphant, who had played a significant role in the development of radar, and thirty of the British scientists who had come to the United States to aid in the atomic project were assigned to the laboratory – some until the end of the war – to work on various aspects of electromagnetic research.

The arrival and processing of each of these groups presented special problems to the area engineer in security and safety, to the laboratory business manager in personnel and finance, and to the laboratory director in program and staff coordination. These problems were further multiplied and magnified by their high turnover rate, the result of the project’s need for scientific expertise at other facilities. As early as 1943, the Army had begun to send many of the contractors’ specialists to the Clinton Works to assist Tennessee Eastman in preparing to operate the electromagnetic plant. The area engineer’s

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staff facilitated their transfer, eventually permanently reassigning a sizable number. Again, in September 1944, the staff oversaw the move of one-third of the British scientists to the Tennessee site.

For the most part, the area engineer’s staff was not directly involved in the many meetings of committee and group leaders who planned research, assessed the results of experimental work, and advised on reassignment of technical and scientific personnel. But the area engineer and other Manhattan representatives did participate in one key group, the Coordination Committee. Business and scientific leaders of the laboratory and representatives of the major contracting firms attended the weekly meetings of this committee, which Lawrence had established to ensure coordination of effort between his program and the many outside organizations collaborating on design and construction of the electromagnetic production plant. After each session Captain Fidler, who had extensive training and experience in both engineering and science, prepared a written report of the entire proceedings to keep General Groves, and other District personnel, up to date on the progress of research and development activities at Berkeley. Whenever Groves visited the laboratory, usually once a month during the crucial period from October 1942 to November 1943, Lawrence convened the weekly committee meeting to coincide with the commander’s itinerary. Feeling that the meetings provided an excellent means of communication with the key members of the laboratory staff, Groves took an active role in the free-for-all discussions of electromagnetic problems.

The area engineer’s staff also carried on a number of other activities, most of them of a routine character. It took part in the negotiation and interpretation of contracts and the review of fiscal plans and policies; assisted in those aspects of personnel administration involving military problems, especially the obtaining of deferments for key scientific and technical employees; expedited procurement of equipment and materials, particularly those in scarce supply; and supervised the more ordinary aspects of security. For example, to avoid any possibility of revealing the connection of the University of California with the Army and the atomic project, Groves always conducted his inspections of the laboratory in civilian clothes. When he arrived at the San Francisco airport, Fidler met Groves clandestinely and whisked him off to his own house so that the general could change from military into civilian attire before going to the university.

Even the remarkably smooth course of the collaboration between the University of California, Berkeley, and the Manhattan District – a testimony to the success of Captain Fidler’s liaison efforts, Groves’ strenuous endeavors to keep himself fully informed, and Lawrence’s exceptional administrative capabilities – on occasion was punctuated with a few problems, primarily because the university administration had to accept Manhattan’s substantial requirements largely on faith for reasons of security. In mid-January 1943, sensing a disruption to normal university activities,

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William J. Norton, the university business manager, complained to Groves in no uncertain terms: “To date I have not seen the scratch of a pen – one written word setting forth the suggestions or directives of the government representatives in regard to the conduct of the Radiation Laboratories on the Berkeley campus. ...” Noting that he was aware that in the past half year several Army officers, including Groves, had visited the campus, Norton continued that “invariably, after one of these visits, ... [my] office is deluged with requests by numerous persons for more office space, laboratory space, entire buildings, shops, more guards, more of this and that – all in the name of the General or the colonel, or the captain who has just visited the various plants. But for some reason I am never in on the discussions at the start.” Norton then assured Groves that he wished to have the project run smoothly, an objective that could be much more easily achieved, he said, if the general would only let him know the importance of the project and who on the campus officially represented the Manhattan District.15

Groves wrote to University of California President Robert G. Sproul, carefully explaining the reasons for the secrecy of the project and for the complicated and sometimes confusing relationships that existed between the Army, the university, and the contracting firms. He then outlined briefly the anticipated requirements for further space in university buildings. “Captain Fidler has been instructed,” he stated, “to keep you [President Sproul] fully informed ... at all times” concerning the physical needs of the project.16 Groves also had requested that the War Department explain to Sproul the importance of the work in progress at the Radiation Laboratory. “[Its] energetic prosecution … ,” Secretary of War Stimson wrote, “is a vital military necessity, for it is one of the foundation stones of an extremely important, probably the most important, development project in our war activities.”17

Not all basic research for the electromagnetic process was done under the University of California contract. In June 1943, District representatives arranged with Tennessee Eastman to carry out research on certain aspects of process chemistry, using laboratory facilities (leased from Eastman Kodak) in Rochester, New York, and at the plant site in Tennessee. Cost of these research contracts, as well as those for process improvement in 1944 with Johns Hopkins and Purdue Universities, were small by comparison with the expenditures at the University of California, totaling considerably less than $2 million.18

Design and Engineering, 1943–1945

At its 25 June 1942 meeting, the S21 Executive Committee decided that Stone and Webster would have primary responsibility for basic design and engineering of both buildings

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Table 1: Stone and Webster Engineering and Design Personnel

Date At Boston At Berkeley In the Field* Total
1 January 1943 239 29 9 277
1 July 1943 738 19 13 770
1 January 1944 743 13 33 789
1 July 1944 685 8 79 772
1 January 1945 463 8 49 520
1 July 1945 338 3 40 381

* Clinton and elsewhere.

Source: MDH, Bk. 5, Vol. 3, “Design,” p. 3.52.

and equipment at the Tennessee site.19 For security, the company formed a separate design organization, which by mid-1944 had nearly 750 employees occupying thirteen floors in four buildings in Boston and, in addition, a subordinate unit at the Berkeley campus and a liaison office at the Tennessee site (Table 1).

To monitor the Stone and Webster design group, the district engineer established in August 1942 the Boston Area Engineers Office and assigned Maj. Benjamin K. Hough, Jr., to head a relatively small staff. From the beginning, one of Major Hough’s most important responsibilities was to ensure that the Stone and Webster design group functioned under maximum security conditions. The special group thus worked separately from other company employees, and overall knowledge of the electromagnetic project was limited to a few key officials and to August C. Klein, the company’s chief mechanical engineer and newly appointed project engineer for the electromagnetic plant. The area engineer’s staff also assisted the company in developing special security control measures in distribution of thousands of drawings to General Electric, Westinghouse, and other firms providing equipment and materials. The designs reflected the emphasis on security and speed in every phase of development. Wherever feasible, Stone and Webster designers planned to use standard items of equipment and customary methods of construction, primarily to save time. There was, however, a limit to the extent that standardization would be possible because of the special character of the processes; the need for exceptionally close tolerances and performance capabilities; and, as proven by experience, inevitable changes in equipment design.20

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By the turn of the year, Lawrence and his staff at the Radiation Laboratory had made significant progress not only in their electromagnetic research but also in the areas of preliminary design and engineering of plant facilities, the results of which they forwarded to Stone and Webster. But before design of the plant could proceed very far, company engineers needed answers to two important questions: How rich in U-235 must the final product be and would a single-stage electromagnetic plant achieve that degree of enrichment? On 4 January 1943, Oppenheimer furnished Lawrence with a tentative answer. The goal, he wrote Lawrence, must be near-perfect separation, that is, production of practically pure U-235 as the final product. Any lesser enrichment, Oppenheimer believed, would require such a large amount of the very heavy uranium that its weight would make it unacceptable for a weapon.21 The degree of enrichment possible with a single-stage plant was not definitely known, but it would not be enough to meet such stringent standards. A second-stage facility might take uranium processed in the original 500-tank plant and bring it to the required higher degree of enrichment.

At the Coordination Committee meeting in early February, Lawrence expressed the view that design of the second-stage might reasonably be delayed for another two months, pending receipt of data on the degree of enrichment attained in the experimental XA calutrons nearing completion at Berkeley. If this data indicated eventual achievement of 70- to 80-percent enrichment, no second stage would be necessary. Groves disagreed. There always had been the possibility that the electromagnetic process would be coordinated with some other isotopic separation process (he probably had in mind the gaseous diffusion plant), and he believed the second-stage facility would be necessary either as a supplement to the first stage of the electromagnetic plant or as part of a plant for enhancing the slightly enriched product from another plant.

As Groves departed from Berkeley on 14 February, he urged that prompt decision should be reached on the Beta process, as it now came to be called to distinguish it from the first stage, or Alpha process. The Radiation Laboratory staff had convinced him that the Beta tanks could probably be designed to make maximum use of Alpha-type equipment, but he needed further assurance from Stone and Webster that a second stage would not delay completion of the first stage.

General Groves and Colonel Marshall conferred with Stone and Webster on 17 March. Marshall took the initiative in securing a firm agreement that the first five Alpha racetracks at the Clinton Engineer Works (CEW) would be identical in design and

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equipment, to guarantee their completion at the earliest possible date. When the company assured Groves that Beta construction would not delay the Alpha units, he gave his approval for the second stage.22

By late spring, design development for both stages was in full swing. The Berkeley, Clinton, and Boston design staffs worked under constant pressure from Groves and other project leaders to produce thousands of blueprints for five Alpha and two Beta racetracks. The emphasis on speed took its toll. Frequently, General Electric, Westinghouse, and the other firms manufacturing components for the racetracks had to incorporate essential design changes after equipment was fabricated and installed, and inevitably some equipment failures occurred. Everyone connected with the electromagnetic project soon realized design, redesign, and process improvement would continue long after the first major units of the plant began production operations.23

By summer, with most blueprints for Alpha I completed and procurement contracts for plant equipment arranged, Groves approved design changes in the fifth Alpha I racetrack. In September, he authorized construction of Alpha II, comprised of four additional racetracks incorporating the improved design (a step recommended earlier by the Military Policy Committee). He also approved two more Beta racetracks, to process the additional output from Alpha II.

Thanks to experience gained on the Alpha racetracks, design of the Beta racetracks posed fewer problems. Beta chemical equipment, however, was quite a different story, because of the small quantities of material undergoing processing and the fantastically high value of U-235. To prevent even a minimum loss of output, the designers made the equipment as small as possible and used corrosion-resistant materials and special devices to recover the last traces of U-235.

With the start of plant construction, continuing design activities assumed a secondary role. Lawrence and his colleagues continued to propose innovations and design alterations in the racetracks, but General Groves consistently followed a policy of approving only changes that clearly would speed up progress. Hence, Radiation Laboratory scientists, in 1944 and 1945, were relegated largely to the role of consultants to Stone and Webster, Tennessee Eastman, and the other contractors, assisting them to improve design and operation of the existing plant facilities.

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Building the Electromagnetic Plant

Actual construction began in February 1943 on a tract of 825 acres located in Bear Creek Valley, some distance southwest of the rapidly growing community of Oak Ridge (Map 3). Project engineers had selected this location because they hoped the wooded ridges paralleling the valley would limit possible lethal effects of a major explosion or similar accident. There was more than ample room between ridges to permit adequate spacing of the numerous plant facilities that, at the height of plant operations, would include nine main process buildings and some two hundred auxiliary structures, comprising nearly 80 acres of floor space.24

Construction Procurement

Stone and Webster had primary responsibility for procuring the materials, equipment, and field construction force needed for building the production plant; however, the Army had directed that the firm consult regularly with the Radiation Laboratory and with the major manufacturing contractors in carrying out materials and equipment procurement.25 Both Stone and Webster and Manhattan officials had agreed that, because of the special nature of much of the equipment required for the electromagnetic process, only the leading manufacturing firms in the electrical equipment field were likely to have the resources and capabilities necessary to supply it.

Consequently, in early 1943 Stone and Webster, with considerable assistance from District officials, negotiated subcontracts with General Electric, Westinghouse, Allis-Chalmers, and several smaller firms to design and manufacture such items as regulators, rectifiers, calutron tanks, diffusion pumps, magnet coils, and vacuum valves that would meet the project’s high standards for workmanship and performance and, at the same time, comply with its stringent procurement deadlines.26

As Stone and Webster negotiated contracts, it also developed an elaborate purchasing organization at its Boston office. This organization worked closely with the Boston Area Engineers Office and, through a procurement unit established at the Tennessee site, with the CEW Construction Division. In addition to the 150 persons employed in Boston and Tennessee, Stone and Webster maintained another 250 representatives in the field at contractor plants and in major industrial areas. These field workers checked equipment for conformity to specifications, expedited deliveries, and assisted in locating scarce materials for subcontractors. Stone and Webster’s procurement organization also worked closely with the Washington Liaison Office, especially in obtaining critical materials,

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Clinton Engineer Works 
Tennessee, 1943–1945

Clinton Engineer Works Tennessee, 1943–1945

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on which it achieved an excellent record of placing most orders within a few days of construction authorization. Maj. Wilbur E. Kelley, a young engineer from Indiana who was responsible for overseeing electromagnetic activities for the Manhattan District, and Lt. Col. Warren George, head of the CEW Construction Division, also kept a watchful eye on procurement. (See Chart 2.)

The sheer quantity and variety of materials and equipment that rolled in by the trainload over a recently built spur track to the construction site taxed the monitoring capabilities of the CEW Construction Division. Starting in the spring of 1943, the builders of the plant moved into the site more than 2,157 carloads of electrical equipment; 1,219 of heavy equipment; 5,389 of lumber; 1,407 of pipe and fittings; 1,188 of steel; 257 of valves of all sizes; and 11 of welding electrodes. The Construction Division was responsible for seeing that all of this material was brought to the site as nearly on schedule as possible. If items arrived early, the division had to help find storage space – not always an easy task because of limited warehousing facilities.

Because parts and machinery could not be fabricated on schedules that dovetailed precisely with construction progress, much had to be accepted as the manufacturers were able to turn it out. Those items that arrived ahead of schedule had to be closely guarded; protected from dirt, corrosion, and other kinds of damage; and carefully inventoried so that they would be immediately available as needed. Chemical equipment posed problems because of special manufacturing and handling requirements, and the equipment often arrived late or just barely on time.

Schedules had to be adapted to last-minute changes in design and to many uncertainties. Discouragingly few items were commercially available. Tanks, magnets, vacuum pumps, cubicles, and most of the chemical equipment, for example, were either completely new in design or so much larger or so much greater in capacity that nothing of the kind previously had been manufactured. Many less obvious items also carried performance specifications that far exceeded anything ever attempted on a commercial scale. For instance, the calutrons required electrical cable that could carry a high-voltage load continuously. The only commercial product that came near meeting this specification was the heaviest X-ray cable, and it was designed to operate intermittently. Even when the commercial equipment could be used, suppliers often had to add to their productive capacity or build entire new plants to furnish the items required in the enormous quantities they were needed. Thus, in the first equipping of the racetracks some eighty-five thousand vacuum tubes were required. In the case of one type of tube, procurement officials ordered in advance the entire national output for 1943 as well as that from a plant still under construction. In the early months of plant operation, when tubes burned out faster than predicted, some feared the racetracks might prove inoperable simply through inability to maintain the tube supply.

New methods had to be developed for machining and shaping the graphite in those parts of the calutron subject

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to intense heat. No standard material would endure the high potentials, mechanical strain, and temperature changes to which bushings in the high-voltage elements in the sources were continuously subjected. After months of investigation, Stone and Webster found an insulator made of zirconium oxide, a new and still very expensive substance. Similarly, use of large quantities of liquid nitrogen to condense moisture created a demand for a substance hitherto not produced on a commercial scale anywhere in the country.

Nowhere were Manhattan District personnel more spectacularly involved in procurement than in the project’s need for vast amounts of silver.27 Because copper was in great demand for all kinds of wartime uses and because silver could serve as a substitute in electrical equipment, Colonel Marshall in the summer of 1942 had detailed Nichols to negotiate an agreement with the Treasury for withdrawal of silver from the United States Bullion Depository in West Point, New York.

District officials arranged to have the silver processed through the Defense Plant Corporation, which was conducting a silver program of its own in connection with other war industries. The silver, in 1,000-ounce bars, was moved by guarded truck to Carteret, New Jersey, where it was cast into billets, and then to Bayway, New Jersey, where it was extruded into strips 5/8ths of an inch thick, 3 inches wide, and 40 to 50 feet long. From Bayway, under the protection of Manhattan District guards, the coiled strips were moved by rail freight to the Allis-Chalmers plant in Milwaukee. There, some 258 carloads of silver were fabricated into coils and bus bars, then sealed into welded casings, and finally shipped on open, unguarded flatcars, by various routes and on irregular schedules, to the Clinton Works.

A central control section in the New York Area Engineers Office administered the silver program, but as a double check the District retained the services of a firm of auditors and a metallurgical concern. Some precautions taken to avoid unnecessary loss included weighing the silver each time it entered or left one of the plants, storing the pieces in stacks that would permit minimum handling during each eight-hour accountability check, and painstakingly collecting the scrap – even the minute amounts that might accumulate on a worker’s clothing or shoe soles.28

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Plant Construction

As work crews began excavating building sites and laying foundations early in the summer of 1943, Stone and Webster foremen knew plant construction must move ahead with maximum speed during the prime summer building season, to meet the extremely short deadlines projected by the Army. Reluctantly, Stone and Webster officials agreed to have the first Alpha racetrack building ready to turn over to Tennessee Eastman, the plant operator, by November and the remaining Alpha units at approximately monthly intervals thereafter. Project leaders were convinced that only adherence to this rigorous schedule would produce sufficient fissionable materials to fulfill the requirements for design and fabrication of an atomic weapon in time to affect the outcome of the war.

Stone and Webster had little difficulty in maintaining force-draft construction schedules for the plant buildings, mainly designed along the lines of structures in common use by industry. The only unexpected delay was the discovery of unfavorable subsoil conditions; excavation crews thus had to do some extra blasting and mucking and laying of 6-foot-thick concrete mats to ensure firm foundations for the enormously heavy electromagnetic machines. Through use of more thorough soil-sampling techniques, Stone and Webster was able to minimize the time lost in providing adequate footings for the later racetrack buildings.

Internal construction of the plant, however, was characterized by unconventional methods and unorthodox problems that seemed certain to cause delays and setbacks in working schedules. Project leaders had anticipated some problems. They knew, for example, that installing equipment while the building shells were under construction was likely to lead to complications because riggers, pipe fitters, and mechanics were not ordinarily accustomed to working elbow to elbow with concrete pourers, form builders, and other building construction workers. Also, security measures and the need to maintain extreme cleanliness in certain areas would require guards and a pass system to limit access to some parts of the buildings. And they well understood that assembling the complex racetrack and other production units involved demanding and time-consuming measures.29

Consequently, Manhattan District officials were pleasantly surprised when Colonel Nichols, who had replaced Marshall as district engineer, reported to General Groves in September that the electromagnetic construction was about 34 percent completed, including the turnover to Tennessee Eastman of the first operational facilities. These were the two tanks and three magnet coils of the XAX development plant with auxiliary supporting units to be used for training production plant workers. At the same time, Colonel Nichols noted that construction on the crucial main Alpha equipment was no more than a few weeks behind the ambitious schedules set up by Groves earlier in the year. Stone and Webster engineers had reported to him that they

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Excavation of typical rocky 
substratum at the Tennessee Site

Excavation of typical rocky substratum at the Tennessee Site

expected the first Alpha racetrack to be operational by 1 December 1943. The only disquieting note in Nichols’s optimistic September estimate was mention of discovery of some “bugs” when the XAX tanks underwent their initial test operation.30

Partly on the basis of this impressive progress, General Groves authorized start of work on four of the improved Alpha II-type racetracks and two additional Beta units in September. Stone and Webster organized a whole new field force and the district engineer reorganized the CEW Construction Division, enlarging its personnel and establishing separate construction divisions to monitor the three major building projects in progress at the Tennessee site: the electromagnetic, gaseous diffusion, and plutonium semiworks facilities. Colonel George continued as head of the newly formed Electromagnetic Construction Division, but with additional officers assigned to branches to monitor Stone and Webster’s nine construction subunits and a special expediting section. Thus, as Stone and Webster’s engineers prepared to carry out a test run of the nearly completed Alpha I unit, District officials were confident that the electromagnetic project was well on the way to successful completion. Had they taken more careful note of the “bugs” that persisted in the XAX calutron test operations, they might have been better

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prepared for setbacks the project was to suffer in the months ahead.31

The first of the unanticipated problems with the newly completed Alpha I racetrack was reported to Colonel Nichols in early November. A few days after they had started test runs, plant engineers discovered that the 14-ton calutron tanks, which stood back to back between the coils, had moved apart as much as 3 inches, causing a tremendous strain on the piping used to maintain a vacuum in the tanks. After investigation they determined that the powerful magnetic field set up in the racetrack had created such a force between the tanks that they “walked” away from each other when they were jarred, as during installation or removal of a door. Following a few days study of the phenomenon, Stone and Webster reported that the adverse effects of the magnetic field could be overcome by installing heavy steel tie straps to hold the tanks firmly in place.32

No such simple solution was possible, however, for the second major problem that the November test operations revealed. The symptoms were intermittent electrical shorts with wide fluctuations in magnetic field strength as successive magnet coils were energized. Colonel Nichols reported the problem to General Groves in early December, by which time the complete failure of several coils seemed to threaten the whole future of the process. Plant engineers indicated that dirt in the oil coolant inside the coils was probably the major cause of the malfunction and the only sure cure was to drain the oil and dry out the coils. Very much upset by the ominous developments, the Manhattan commander directed Nichols to take all measures necessary, pending his own arrival at the site to discuss such other steps as might be required, including “a reorganization of personnel in charge of the Y-12 [electromagnetic] construction work so that similar occurrences [would] be avoided in the future.”33

Groves arrived at the Clinton Works on 14 December for a hurried two-day inspection visit. On hand already were project engineer August Klein from Stone and Webster and a team of experts from Allis-Chalmers, where the unsatisfactory coils had been manufactured. Their further checking, Groves learned, had revealed that the trouble stemmed not only from mill scale and rust in the cooling oil but also from moisture in the cloth and fiberboard insulation, and too close winding of wire. Groves set in motion a thorough reorganization of the Clinton electromagnetic administrative team and reemphasized his earlier directive to Lawrence that he concentrate Radiation Laboratory resources on finding a solution for the defects in the racetrack equipment.34

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Alpha I Racetrack, 
Electromagnetic Plant, CEW

Alpha I Racetrack, Electromagnetic Plant, CEW

A new administrative hierarchy resulted from the reorganization of the electromagnetic team, which took effect in January 1944. Lt. Col. John S. Hodgson, who had considerable experience as a civilian contractor, replaced Colonel George as chief of the Electromagnetic Construction Division; Maj. William A. Bonnett moved up from a position as a liaison officer with Stone and Webster field units to be Hodgson’s assistant; and Maj. Walter J. Williams, who had had assignments on a number of ordnance plant construction projects, took over responsibility for completion of the original electromagnetic plant. Only Maj. Mark C. Fox, who had served as area engineer on other Corps of Engineers projects, continued in his recently assigned task of overseeing construction of extensions to the original electromagnetic plant. At the same time, Stone and Webster brought in Frank R. Creedon from the synthetic rubber program to be general manager of all the company’s operations at the Clinton Works. Creedon had had an earlier association with General Groves, having worked as a civilian employee of the Army’s Construction Division on ordnance projects before 1942.

The first big task facing the new team was how to solve the technical defects in the Alpha I electrical equipment. Project technicians decided the only sure remedy was to return the malfunctioning magnet coils to Allis-Chalmers’ Milwaukee plant for cleaning and rewinding, as well as to have equipment crews disassemble and

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clean all oil lines in the racetrack building. It took about three months to complete these corrective measures, and thus the first Alpha I racetrack was not fully operative again until early March 1944.35

With the distressing days of technical problems in the past, by spring the somber mood of Manhattan and Stone and Webster officials concerning the electromagnetic method had dissipated, and they were enjoying a revived sense of optimism. One argument in favor of the process had been that the production plant could be built in segments which would become operational as soon as they were completed, making possible the early detection of defects and the addition of indicated improvements. And now, because the trying experiences of Stone and Webster engineers with the first Alpha I racetrack had enhanced their understanding of the problems and the reasons for them, they were able to make changes in equipment handling and installation techniques for subsequent racetracks. On the second Alpha I racetrack, for example, the engineers introduced much more rigid standards of cleanliness, including such measures as drying out pipe lines by circulating preheated oil through them and adding filters for each coil.36

Initial failure of Alpha I also reaffirmed a cardinal principle of General Groves’ administrative policy for the atomic project. For months, the Manhattan commander had been emphasizing that the major resources and personnel at the atomic research laboratories should be concentrated on the single objective of securing production of militarily significant amounts of fissionable materials in time to be of use during the war. On more than one occasion during his visits to the Radiation Laboratory in the fall of 1943, Groves had reminded Lawrence’s scientific staff that the Army was not interested in advancing pure science. Their mission, he stated, once the research and development for the production plant was completed, was to support in whatever way was necessary the design, construction, and operation of that plant. The natural tendency of the Radiation Laboratory scientists was to resist limiting themselves solely to so-called debugging activities for the Tennessee plant, but the crisis caused by Alpha I’s failure forced Lawrence to push new research entirely into the background and, in December, to completely redefine laboratory priorities in terms of two objectives: increasing the output and efficiency of the electromagnetic plant; and developing new ideas, methods, and engineering designs for expanding that plant.37

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The Army’s prompt administrative measures to counter the adverse consequences of Alpha I’s failure proved to be highly effective. The engineers were successful in making the second Alpha I operational by the end of January 1944, the first Beta and the first and third Alpha I in March, and the fourth Alpha I in April. Impressed with the rapid progress being achieved, Colonel Nichols reported to Groves that he was now convinced that the prediction given to President Roosevelt in December 1942 – com- pletion of an atomic weapon by early 1945 – would be realized if persisting manpower shortages could be overcome.38

Meanwhile, Stone and Webster had been moving ahead with construction of other major elements of the electromagnetic plant. Construction time for building the extension units – the Alpha II racetracks – was far less in comparison to that required for Alpha I. The Stone and Webster crews’ rapid progress was in part due to certain design modifications, such as using cement asbestos brick for the outer siding of buildings and making the racetrack shape rectangular rather than oval. Also, the experience gained on Alpha I expedited installation of equipment in Alpha II. The first racetrack in the extension plant began operating in July 1944 and all four were ready for operation by 1 October.39

At the same time, Stone and Webster and its subcontractors constructed the Beta units, where the Alpha-processed material would be further enriched, and built the facilities for chemical preparation and recovery for both Alpha and Beta plants. In spite of several changes in plans, resulting in considerable expansion of the Beta and chemical facilities, the Electromagnetic Construction Division kept the work on or even ahead of schedule, avoiding delays in processing material from the Alpha plants. From original plans in 1943 for only a single Beta unit to process Alpha I output, the number grew to four: one for Alpha II; another to handle additional output from Alphas I and II that resulted from using partially enriched feed material from the gaseous diffusion plant; and still another in 1945 so that there would be enough Beta facilities to process enriched material coming directly from the diffusion plants. Similarly, each expansion of the Alpha and Beta units required an increase in the number of chemical and other processing facilities, giving the division additional work in expediting procurement, monitoring revision in contracts, and inspecting completed construction. This continuing high-level of construction activity occasioned Colonel Hodgson to reorganize his division in late 1944 and to establish five separate branches (structures, electrical, expediting, process piping, and mechanical). Not until early 1945, when the Military Policy Committee decided that the indicated successful operation of the gaseous diffusion and plutonium plants would make further large-scale expansion of electromagnetic production

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Electromagnetic plant under 

Electromagnetic plant under construction

facilities unnecessary, did the division’s workload ease significantly.40

Plant Operation

Terms of the June 1943 contract for operation of the electromagnetic plant provided that Tennessee Eastman operate it on a cost-plus-fixed-fee basis, serve as a consultant on plant design, obtain and train operating personnel, and carry on research to improve the process and its product. For performing these services, the government agreed to pay the firm a basic operating fee of $22,500 each month plus $7,500 for each racetrack up to seven and $4,000 for each one over that number.41

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In early 1943, when Tennessee Eastman initiated preliminary operational activities at the Tennessee site and at the Berkeley and Rochester research facilities, the district engineer formed a CEW Division in the New York office and assigned Major Kelley as division chief to supervise electromagnetic operations. Kelley’s division not only monitored the contractor’s activities relating to administration, chemical processes, electrical processes and plants, and special accounts but also established liaison with its Berkeley and Boston administrative units that coordinated with the Radiation Laboratory and Stone and Webster. Tennessee Eastman’s Boston staff, however, moved to the Tennessee site in August, in keeping with the firm’s frequently expressed desire to center its plant operations activities there.42

During construction Major Kelley and his operating unit staff were busy assisting Tennessee Eastman in recruiting and training personnel to operate the Alpha, Beta, and chemical process equipment. Early estimates of the number of employees needed were far too low and requirements were repeatedly revised upward. Although recruiting was carried on in all sections of the country through regional offices of the United States Employment Service, the best results were attained in Knoxville and vicinity. For the many jobs requiring technical knowledge and background, the electromagnetic project had to resort to procurement through military channels. Many of the scientifically trained personnel in the Manhattan District’s Special Engineer Detachment (SED) at the Clinton Works were assigned to work in the plant, reaching a total of 450 SED enlisted personnel by August 1945. The District also assisted in the temporary assignment of technically trained Navy officers to the plant in 1944, their number reaching a maximum of 143 in July of that year.43

Tennessee Eastman made a major effort to develop a training program for the thousands of operators who would be required when the plant was ready for full-scale operation. Working closely with Radiation Laboratory scientists, the firm’s Berkeley staff laid the groundwork for systematic training of workers and supervisory personnel. While many practiced with the Alpha experimental equipment at Berkeley, others went to the University of California’s Davis campus to learn chemical processing techniques. Radiation Laboratory scientists and Manhattan District representatives carefully reviewed all training material, the latter group giving special attention to the security problem. Tennessee Eastman technicians deliberately compiled the training material to give the would-be operator only the information needed to perform

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the job, without revealing the true character or purpose of the end product. Experimentation demonstrated that trainees with preliminary orientation in the nature of the electromagnetic process made the most rapid progress. Meanwhile, by September 1943, intensive recruiting efforts by the company had resulted in the hiring of some eighteen hundred operator trainees, most of them from the Knoxville area.

Some preliminary instruction took place in facilities of the University of Tennessee, because the large-scale training program at the plant site did not start until early fall. By that time hundreds of trainees were on hand to begin training on two experimental XAX electromagnetic production tanks that had started operating in the development plant. Tennessee Eastman moved all but a few of its personnel from Berkeley to the Tennessee site to participate in training the twenty-five hundred operators deemed necessary for the five Alpha I racetracks. With the addition of the Alpha II and Beta buildings, the trainee program expanded to provide several times that many operators. By early 1944, Tennessee Eastman’s payroll had increased to ten thousand and by mid-1945 it would rise to more than twenty-five thousand.

The typical operator trainee was a woman, recently graduated from a nearby Tennessee high school, with no scientific training whatsoever. Using one of the XAX electromagnetic tanks in the development plant, the instructional staff taught her how to operate complex control panels in the calutron cubicles adjacent to the racetracks. They gave her only information essential to her task as an operator and, for security reasons, actually mislead her as to the real purpose and character of the product. The training program was surprisingly successful, supplying operators on schedule for each Alpha and Beta racetrack as it went into operation.

Production Activities

Starting up in late 1943, the electromagnetic chemical units eventually were producing thousands of pounds of the charge material necessary for the production operation of the racetracks. The first really effective production of the U-235-enriched final product came in late January, when the second Alpha I racetrack began operating. In the five-month period following, as the remaining three Alpha I and the first two Beta tracks became fully operational, production steadily increased. And by mid-1944, the Army could view the electromagnetic start-up operations as, in the main, successful.44

Manhattan District officials, however, were unprepared for the almost continuous problems that arose as the electromagnetic plant moved into the sustained production phase of its operation. One mechanical or equipment failure after another plagued plant operations; short circuits and shortages, breakdowns and breakages cropped up on all sides. In spite of the best efforts of Tennessee Eastman and District procurement officials, the spare parts situation skirted the edge of chaos for months. Lack of experience, of standardization, and of a sufficient

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CEW training facilities ( 
background), where electromagnetic plant employees received preliminary instruction

CEW training facilities ( background), where electromagnetic plant employees received preliminary instruction. District headquarters buildings are in the foreground

number of suppliers all contributed to the severe parts procurement difficulties. Nevertheless, the District’s electromagnetic staff and Tennessee Eastman – working in close coordination – managed sufficiently to overcome the adverse effects of these many problems so that in March 1944 plant workers shipped the first of several hundred grams of Alpha product, containing 13 to 15 percent U-235, to Los Alamos. Three months later the first shipment of the much more highly enriched Beta product reached the New Mexico laboratory.45

But Manhattan and Tennessee Eastman officials were well aware that this output of sample quantities represented only the first steps in bringing the electromagnetic plant up to a maximum rate of production, a complicated undertaking with pitfalls at every turn.46 They readily perceived that part of the difficulty was inherent in the basic nature of the process that used large complex machines and significant quantities of electric power and raw materials to isolate an infinitesimally small amount of final product. The basic feed material, orange-colored uranium oxide shipped in from refineries operating under direction of Manhattan’s Madison Square Area Engineers Office, moved through a series of very complex steps. A chemical preparation process converted it into a gaseous form, uranium tetrachloride, which plant workers

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then fed into the Alpha racetracks. Here part of the feed material separated, while the rest adhered to various parts of the interior of the calutron, where it had to be recovered for recycle. The separated portion went to the Beta chemical preparation stage and then into the Beta racetracks for further separation. That separated portion emerged as U-235 final product and, after concentration, workers shipped it to the Los Alamos Laboratory. The rest had to be recovered, recycled through the Beta racetracks, and concentrated for shipment.

Only 1 in 5,825 parts of charge material fed into the Alpha racetracks emerged as final product; 90 percent of the charge material was left in the feed bottles or scattered around the tanks. Of the 10 percent that passed into the ion beams, only a very small quantity entered the receivers. The amount reaching the receivers was limited by the capacity of the calutrons. It could not be increased except through use of enriched charge material, or by construction of more racetracks. Furthermore, the amount actually recovered from the receivers, because of its minute quantity and the essentially violent nature of the process, could not be made to reach 100 percent even by the most practicable methods.

Because of the high intrinsic value of the final product, recovery had to be as complete and thorough as possible, yet with no undue holdup time in the chemical apparatus to slow down the process. The Beta chemistry facilities included a salvage department which used batteries of extractors, reactors, filters, centrifuges, evaporators, and driers so that the very last traces of enriched uranium might be recovered. Justification for these intensive efforts was demonstrated when worn-out carbon receiver parts from the calutrons were burned. They yielded enough enriched uranium to raise the January 1945 production a full 10 percent.47

Even under the best of conditions, a small amount of U-235-enriched product always remained in solutions, or bound in solids, or adhered to costly and scarce equipment parts; however, it was economically unfeasible for this material to be recovered. A certain percentage also remained in that part of the uranium feed matter which passed through the ion beam but did not enter the receivers. It was imperative that this material – constituting nine-tenths of the uranium fed into the Alpha calutrons and seven-eighths of that going into the Beta racetracks – be prevented from contaminating the enriched uranium and be recovered and stored for possible future reprocessing. To keep losses at a minimum and to prevent theft, Tennessee Eastman instituted a strict material accounting system. Stock room employees inventoried the Alpha stocks every four weeks, the Beta every two weeks. In spite of this careful check, surprisingly large amounts of material (17.4 percent of Alpha product by September 1945 and 5.4 percent of Beta product by December 1946) were lost unavoidably in the various kinds of wastes created by the separation process itself.48

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The most crucial phase of the recovery operation took place in Beta chemistry. Alpha workers moved the final Alpha product, stored in receiver pockets on the removable doors of the Alpha calutrons, to the Beta chemistry buildings. After dismantling the pockets, Beta workers first scraped, bleached, and burned the graphite parts and then leached and electrostripped the metal parts. Finally, chemists processed the resulting solutions and solids to extract all enriched uranium. They then purified this enriched uranium and converted it into Beta feed material.

The Beta preparatory chemical process proved to be one of the most persistently troublesome operations in the electromagnetic plant. The process was slow, requiring, even under optimum conditions, about three weeks. More worrisome, however, only about 60 percent of the enriched uranium brought from Alpha was showing up as an end product of the Beta chemical process, causing a serious shortage of feed material for the Beta racetracks. In July 1944, Groves himself went to the Clinton Works to discuss the problem with plant and District officials. As a result, Tennessee Eastman temporarily shut down all Beta production in August so that company engineers and outside consultants could thoroughly analyze the process and equipment. Their investigations revealed that the trouble lay in the overly complex piping and equipment and in the tendency of certain materials in this equipment to absorb too much uranium.

District and Tennessee Eastman officials immediately instituted changes in equipment, techniques, and organization to overcome these weaknesses in Beta chemistry. Project engineers set about removing, cleaning, and redesigning piping; replaced glass-lined tubes with pyrex; put in more parts made of graphite from which absorbed uranium could be recovered by burning; and made other changes to speed up the process. For varying periods during the fall of 1944, experts like Frank H. Spedding, the metallurgist who headed Manhattan’s research program at Iowa State College, and John P. Baxter, one of the British scientists assisting in the bomb development program, came to the Clinton Works to study Beta chemistry with an eye to improving techniques employed in the process. And, in December, District officials negotiated contracts with Johns Hopkins and Purdue Universities to study methods for increasing recovery and reducing holdup time in the Beta process. Tennessee Eastman, now more fully aware of the chemical difficulties of isotopic separation, completely reorganized its Clinton chemistry division and greatly increased the number of personnel.

In spite of the difficulties with Beta chemistry operations, in January 1945 the district engineer reported to the Manhattan commander that there had been a dramatic increase in Beta production during the second half of 1944, with output being about 60 percent greater at the close of December. This increase was attributable primarily to the much higher productive capacity of Alpha II calutrons, and the fact that all Alpha II’s were

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fully operational by November. Consequently, Beta output in November was more than ten times the July rate, increasing even more in December to twice the November rate. The Alpha II’s, however, were far from trouble-free. The major problem experienced had to do with the insulators burning out at a high rate, but the engineers quickly corrected this defect by recommending that zircon be substituted for the less durable material in the bushings.49

Not all of the production problems of the electromagnetic project were mechanical or technical in nature. When the spare parts crisis occurred in June 1944, Groves looked into project management by Tennessee Eastman and District officials. Following a visit to the plant, he wrote to Conant that he had observed a number of ways in which he thought production might be increased. Supervisors ought to make more frequent inspections, especially in installation and servicing of calutrons. More should be done to build up and maintain employee morale. Lack of sufficient organization charts and the presence of “too many people” in the operating rooms gave Groves the impression that the plant managers were not making the most efficient use of personnel. Also, he wondered if Frederick R. Conklin, the Tennessee Eastman works manager, and Major Kelley, chief of the District’s Electromagnetic Operations Division, were “too similar in disposition,” noting that neither Conklin nor Kelley was a “hard driving, optimistic executive. Instead of setting an impossible goal and then breaking their hearts to almost achieve it, they set a nice, comfortable goal making plenty of allowances for difficulties and then feel very proud of themselves for having been proven right in their pessimistic outlook.”50

General Groves took no immediate steps to institute major changes in management. He could not overlook the fact that Major Kelley got along extremely well with the key executives of Tennessee Eastman and also was held in very high regard by Lawrence and the staff of the Radiation Laboratory. It was not until September, with the spare parts problem partially relieved and the Beta chemistry bottleneck on the way to solution, that the Manhattan commander directed the district engineer to replace Kelley. Colonel Nichols selected Lt. Col. John R. Ruhoff, a chemical engineer by profession, because of his familiarity with electromagnetic problems; he had been assistant chief of the District’s Materials Section and, since 1943, chief of the Madison Square Area Engineers Office where he was responsible for overseeing the provision of feed materials for the electromagnetic process. In early 1945, Ruhoff assumed responsibility for overseeing all electromagnetic activities at the Clinton Works and continued in that post until the end of the war. Major Kelley did not leave the

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Electromagnetic plant in 
full operation

Electromagnetic plant in full operation

Manhattan Project, but replaced Ruhoff as head of the Madison Square Office.51

Although there was a gradual, but not spectacular, improvement in electromagnetic production, intermittent expressions of dissatisfaction with the way the plant was operating continued. For example, British scientists working at the Radiation Laboratory came away from a visit to the plant highly critical of certain design features of process equipment and of the alleged gross inefficiency of the service crews. Marcus Oliphant, head of the British group, also found serious fault with personnel and organization.

He wrote to Sir James Chadwick in November 1944, expressing concern at the “poor quality of the higher grade personnel in TEC [Tennessee Eastman Corporation] ... [and] the clumsiness of the army organization, which neither controls nor checks the operation except in a very desultory and inefficient manner.”52

Partially as a reaction to this continuing criticism, but chiefly as a reflection of frayed nerves under the long strain, Tennessee Eastman executives complained bitterly in April 1945 to Brig. Gen. Thomas F. Farrell,

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who had been serving as Groves’ deputy since February, that the firm was not getting the recognition it deserved for what it had accomplished at the Clinton Works. Operation of the electromagnetic plant should be viewed for what it actually was, a huge pilot plant, not a normal industrial operation. While, undoubtedly, there were deficiencies that the firm could correct, there were also handicaps which it could not possibly overcome. The plant had been designed with few interchangeable parts; the damage to equipment had been greater than projected; and the program had been constantly changing, as in the case of the recent shifts to thermal and gaseous diffusion feed materials. In the light of all these mitigating factors, they were especially disturbed by the implication of General Groves’ remark to the operating supervisors that “they should work until they fell into their graves just as the war was over.”53

The criticisms and complaints began to lose some of their sting by late spring of 1945 as rapidly increasing production provided concrete evidence that the plant was going to be a success. In January, all the racetracks had demonstrated their ability to perform at predicted capacity, even though delays in servicing, chemistry, and procurement of parts still imposed a drag on full production. In February, the first slightly enriched (1.4 percent) uranium feed had come from the new thermal diffusion plant, and in March the first enhanced (5 percent and up) material from the gaseous diffusion plant. In April, the gaseous plant began turning out uranium sufficiently enriched to go directly into the Beta racetracks, gradually increasing product enrichment until it reached 23 percent on 5 August: the day before the first bomb was dropped on Japan.

Because of the higher enrichment of the Beta feed material, the Alpha stage was no longer necessary. In early September 1945, with the occupation of Japan going forward successfully, plant officials ordered the Alpha racetracks shut down. They had produced more than 88 kilograms of final product with average enrichment of 84.5 percent. Beta continued in operation until the end of the year, producing an additional 953 kilograms of final product with an enrichment of about 95 percent.54